private void _treeCtrl_ItemDrag(object sender, ItemDragEventArgs e)
{
// the item being dragged should be selected as well.
BindingTreeNode node = (BindingTreeNode)e.Item;
_treeCtrl.SelectedNode = node;
ItemDragEventArgs args = new ItemDragEventArgs(e.Button, this.GetSelectionHelper());
EventsHelper.Fire(_itemDrag, this, args);
}